Moses and Aaron represent two kinds of leader.
The difference between them only reinforced the bond, cemented an alliance and a lasting friendship.
At the same time, Moses never could descend altogether from the higher sphere; he did not even try to be liked or understood by the people.
His whole essence, from the start of his career, was one of aloofness, almost that of the stranger or the one who comes from above.
As the Torah commentator Avraham Ben Ezra put it, "It was decreed in heaven that Moses should grow up in the royal household so that he could appear to the people as a king."
Aaron, however, was not only the assistant or the translator.
True, he did provide Moses with help and support, but was also a leader in his own right, as is apparent from any scrupulous reading of the text.
He was the popular chief, one of the tribe, a Levite, and a spokesman.
Because he understood the people and sympathized with their shortcomings, he could guide them toward a goal that Moses had reached in a different way.
Moses operated from the higher to the lower: he was the authority figure, giving orders and hardly ever explaining or educating.
Aaron, on the other hand, functioned from the lower to the higher, trying to lead the people carefully, teaching and guiding them.
–Rabbi Adin Steinsaltz
From Biblical Images by Rabbi Adin Steinsaltz